Fluid cushioned clutch mechanism



Dec. 16, 1952 WALES 2,621,480

FLUID CUSHIONED CLUTCH MECHANISM Filed Jan. 28, 1949 8 Sheets-Sheet lJNVENTO BY fwg K.

Dec. 16, 1952 G. F. WALES 2,621,480

FLUID CUSHIONED CLUTCH MECHANISM Filed Jan. 28, 1949 8 Sheets-Sheet 2INVEgM B. Z

G. F. WALES I FLUID CUSHIONED CLUTCH MECHANISM Dec. 16, 1952 8Sheets-Sheet 5 Filed Jan. 28, 1949 Dec. 16, 1952 e. F. WALES FLUIDCUSHIONED CLUTCH MECHANISM 8 Sheets-Sheet 4 Filed Jan. 28, 1949 G. F.WALES FLUID CUSHIONED CLUTCH MECHANISM Dec. 16, 1952 8 Sheets-Sheet 5Filed Jan. 28, 1949 v Q mN m mm %w w Rh 1 .0 III am m6 J g M M w Y. I NN Qm mw WW Dec. 16, 1952 e. F. WALES FLUID CUSHIONED CLUTCH MECHANISM 8Sheets-Sheet 6 Filed Jan. 28, 1949 Dec. 16, 1952 G. F. WALES 2,621,480

FLUID CUSHIONED CLUTCH MECHANISM Filed Jan. 28, 1949 8 Sheets-Sheet 7Dec. 16, 1952 WALES 2,621,480

FLUID CUSHIONED CLUTCH MECHANISM Filed Jan. 28, 1949 8 Sheets-Sheet 8Patented Dec. 16, 1952 UNITED STATES PATENT OFFICE FLUID CUSHIONEDCLUTCH MECHANISM George F. Wales, Kenmore, N. Y.

Application January 28, 1949, Serial No. 73,271

30 Claims.

This invention relates to power transmitting devices, being concernedmore particularly with such a device wherein the movement of a drivingmember is transmitted hydraulically to a driven member.

The transmission of energy from a prime source of power to a source ofwork has universal application in the mechanical art. The two basicelements for transmitting energy are revolving or reciprocating membersand in most all types of mechanisms these basic elements are intermixedto provide the desired characteristics. For instance: in many mechanicalapplications a power driven revolving shaft is caused to drive a gear orother rotary type fluid pump whereby fluid under pressure may be appliedby means of a multiple port valve to either side of a piston so as tocause it to reciprocate intermittently under control of the valve. Amechanical counterpart of the above arrangement comprises a revolvingeccentric which imparts reciprocal movement to a member restrained tolinear movement. In this latter construction a clutch is generallyplaced before the rotating eccentric so as to engage or disengage itfrom the source of power to perform the function of the valve in thehydraulic apparatus. In the first arrangement, the limit on fluidvelocity due to pump capacity, frictional losses of the pipes, etc.,results in a comparatively slow cushioned movement of the reciprocatingpiston. In the second arrangement a fast action is possible but theengagement of the mechanical parts results in high shock loads on thedriving and driven elements.

In many applications in the mechanical field, the advantages of both ofthese systems, i. e., cushioned action with high speed; could be appliedbut heretofore such an arrangement has not been economically feasible.

It is the primary object of my invention to provide high velocityintermittent fluid cushioned power transmission.

Another primary object of this invention is to provide a simple,economical apparatus for transmitting energy to a reciprocating memberwhich is positive in action and rugged. and durable in use.

It is another object of this invention to provide a simple, fluidcushioned powertransmission mechanism.

A companion object of this invention is to provide a quiet mechanismwherein all the mechanical engagement noise is eliminated.

"Still another object of this invention is to provide a simple integralmechanism which may be 2 assembled or disassembled as a unit': from amachine.

Yet another object of this invention is to provide a mechanism which maybe easily serviced.

Still a further object of this invention is to provide an integralmechanism adapted to be positioned adjacent the work area of a machinewhereby the customary actuating linkage may be dispensed with.

Still another object of this invention is to pro vide a selff'containedsequence assuring mechanism for actuating a reciprocable member.

A related object of this invention is to provide a fluid actuatedreciprocable mechanism which can be utilized on a high speed machine.

A companion object of this invention is to provide a mechanism requiringless space.

Still a further object of this invention is to provide an integralpressure pad in a clutch mechanism for a press which provides for deepdrawing of material when required.

A companion object is to provide a mechanism providing variable strokeor pressure.

Other objects and advantages of this invention will appear from thefollowing descriptions and claims. I

Fig. l is a perspective view of my machine element showing the eccentricdriving means.

Fig. 2 is an exploded perspective view, in partial section of oneversion of my novel actuating mechanism.

Fig. 3 is a front elevational view in partial section which illustratesthe idling condition of this mechanism and the fluid working and reservechambers.

Fig. 4 is a sectional view taken as noted along line 44. of Fig. 3 whichillustrates the concentric fluid working and reserve chambers and theports which permit the fluid to course from rev serve to workingchambers.

Fig. 5 is a view similar to Fig. 3 with the elements illustrated at themoment of actuation.

Fig. 6 isa view similar to Fig. 5 but with the elements sealed so thatthe fluid in the working chamber is trapped to cause the reciprocatingpower thrust.

Fig. 7 is a, view similar to Figs. 3 and 5 illustrating the cylinder atits lowermost position of operation.

Fig. 8 is a like view essentially similar to Fig. 6 except that the portarea is about to be uncovered as thecylinder returns to its uppermostposition.

Fig. 9 is a partial sectional view which illustrates how this apparatuscan be revised by the Fig. 12?) illustrates the filling of the working.

chamber from the suction action of the piston so that the fluid can beentrapped on the actuating stroke.

Fig. 120 shows the movement of the components of apparatus to effectreciprocal power transmission and illustrates that the fluid issealedofias is illustrated inFig. 6.

Fig. 12d shows the apparatus at the. bottom of-thestroke, as shown inFig. 7. I

Fig. 126: shows the return of the ported cylinder and the opening of itsport area for the reciprocation of the fluid.

Fig. 12 shows the reciprocable cylinder retained in its upper-position,the fluid being forced out at the beginning of the continuous idlecycle, illustrated in Fig. 12a.

Fig. 13 shows how this apparatus can be adapted to use on apress-working machine tool, so as to providethe intermittentpress-working stroke. r

In Fig. 1 it will be noted that I employ a revolving eccentric 24- onthe extremity of a shaft 44 to provide a continuous reciprocation. Apitman 25 is utilized to transmit this constant reciprocation to apiston 25 within my novel mechanism. It will be obvious to those skilledin the art that any method for reciprocating piston 26 can be used andthat the method here illustrated is irrelevant to the successfuloperation of my apparatus. Referring also to Fig. 2, the exploded view,it will be noted that piston 25 is joined to pitman arm 25, which is notillustrated in this view, by means of holes 28 in the piston, an axiallyaligned hole in the pitman arm, and a pin 68 which engages in theseholes and which has also been omitted from this view for clarity. Thepiston 26 is reciprocally driven within the recinrocable portedcylindrical member 36. Ported cylindrical member 38 consists ofa closedcylinder with a pl rality of ports 31. Piston 26 is slidable within theupstandin cylindrical section 35 of member 36. has a seal ring 6! whichis not shown herein so that its retaining groove 6 la can beillustrated, and a shoulder portion 28 for engaging the lifter ring 3i]when it is threadedly engaged in the internally threaded portion 48 ofthe upstanding sleeve 35 of the reciprocable cylindrical member 36. Inthe idling condition of my apparatus, piston 26 is reciprocatingcontinuously within the reciprocable cylindrical member 38 and the fluidis coursing in and out of ports 31 as will be discussed later inconnection with the small iagrammatic view of Fig. 17a. In thiscondition the reciprocable cylindrical member 35 is maintainedstationary because of the engagement of pin 45 with the bore iii, in thecylindrical sleeve 35 of member 36. It should be noted that bore 4|- ispositioned so it is not visible in this view;

Having discussed the basic construction features of my apparatus, I willnow-refer t0. dia- Piston 2'6 4 grammatic views, Fig. 1211 through 12which illustrate th operation of my novel apparatus.

As previously described, Fig. 12a illustrates the piston 26reciprocating freely in the reciprocable ported cylindrical member 36,because of the action of eccentric 24 of shaft 44 and the connectingpitman arm 25. In this attitude the fluid 21' is coursing back and forththrough ports 31 of the ported cylindrical member 36: which is heldstationary by pin 45.

Fig. 12b shows the eccentric 24 of shaft 44 at its uppermost position,at which point the reciprocable ported cylindrical member 36 is releasedby means of some mechanism such as lifter ring 30 which lifts ram 36 andpermits withdrawal of pin 45 in my disclosed apparatus, so that it willdrop and, seal the ports 31, While maintaining itself in juxtapositionto the stop 29 of the reciprocating piston 28, so as to entrap the fluid21 which is contained between piston 26 and the ported cylindricalmember 36.

Fig. 12c shows the eccentric 24' of shaft 44 in a downwardly displacedposition thereby moving coupled piston 26, and thus permitting thereciprocable cylindrical member 36, which is'resting against piston stop29- to drop to the sealed position of ports 31. V

It will now be obvious tothose skilled in the art, that since a portionof the fluid- 2? is entrapped between the reciprocating piston 26 andthe reciprocable cylindrical member 36, that piston 26 and cylindricalmember 38- will now move in unison against the resisting force of anymachine or apparatus. It' could operate a cutting tool, punch or othertool, or any-machine element attached to member 36.

Fig. shows the eccentric 24 of shaft 44 in its lowermost position withthe piston 26- and the juxtaposed cylindrical member 35 at the bottom ofthe power stroke.

Fig. 126 shows the eccentric 24- of shaft M on the return stroke withthe ports 31 of the reciprocable cylindrical member 36 gradually beinguncovered.

Fig. 12) shows the reciprocablecylindrical member 36 again retained inits stationary posi tion at the topof its stroke by virtue of pin 45which engages ram 3.6as shown in Fig. 3 with the piston 26 againreciprocating relative thereto, so as to exhaust the fluid 2T through:ports 31 in the action previously described in Fig; 120:.

Reference now will be made to Fig. 3 and Fig. 4, to illustrate ingreater detail, some of the con struotional features of this mechanism.It will be observed that reciprocable cylindrical member 36 has seals 63and 64 shown in cross-seeition, on either'side of the port 3 to effectseal-.- ing when cylindrical member" 35. is caused to drop. It will befurther observed that cylindrical portion 38 in which member 35reciprocates, is threadedly engaged in housing 3] to effect adjustmentof the port opening in the event fluids of greater viscosity areutilized which require maximum port openings. The seal 48 prevents aleakage of fluid therebetween. It will be noted that a check valve 59 isprovided by means of ball 5! which allows air to enter above fluid 21through the port opening 2, but prevents the ejection of air and vaportherefrom. This has proven to be important with regard to the un-'hampered movement of the reciprocabl cylindrical member 33- as will bediscussed hereafter.

The desired downward movement of the reciprocable cylindrical member 38,described hereto- .fOre, is assured becauseof its own weight,*Withamass;

causerunder the heatrofoperationv relative moves ment or?thereciprooable cylindrical member is more? di-fii'cult. there is some:leakage mast.

the seal rings, this internal pressure maygescape when; the machine. is.idle. If the piston 26 stopped at. the bottom or itsstroke;-- when:reciprocation :washalted the initial movement of: piston 2'6 will createa reducedinternal. pressure: inhousing 3t which will. preventthemovementoi 'recip-rocable cylinders 36- until. the internal.-pressnrel is. built up as pnavicmslsr.'- described;

However; the check valve; 5&- provides; the. instant. relief; of. this;reduced pressure and thereby": pres vents:- this. malfunctioning It"will be also? obviews. that: valve 50-could be. omittedby prov-id ing.avent. opening in housing, 3| but'the. noise and vapor'emitting;therefrom might prove; ob-- jectionabler: It. likewise follows thatin.horizontalor" inverted installations check. valve 50 couldhe replacedwith.- a .sourceof fluid pressure;

tocassure. movement ofIcyl-indrical member. 35 by overcoming-its.inertia;

'Itlwillalso be-obviousto thosea-skilled in the. art,; that thelengthoithepower stroke isfdependent; upon the amount .of. fluid trapped be--tween piston .ZEandJmember and that order toobtain. themaximum .strokeitwillbe. necessary. tohavethe. chamber formed. therebetweenfllled;completelyi. To assure this sequence. of; opera.- tion or timing, thelifting. ring,;30. threadedly en. gagesa cylindrical portion 35? ofmember 36. and is: adjusted so that the' upstanding. shoulder" 29: of.piston 26 just lifts "the reciprocahle cylindrical. member36isufficiently, at the top of the. stroke. against the internalpressure of the apparatus created due to the. expansion of the vaporand'ai'r above fiuidZ'l and acting. againstfmemher 36; to permit" thewithdrawal' oi'fpin' .45 at this point; thus: timing. the dropping. ofreciprocable member 36" to thereciprocal'movement. of." piston 261:0assure the maximumfiixidcolumn and length. oilstroke; As shown in 3;.pin: 45 primarily'serves as a. holding means for; preventing themovement,of'membergib reciprocation" of piston 26. However,,..rei ferring; to Fig; 5, its other function is to timetljiefse quence" ofoperation of: member 3 6 in combination" with" the internal pressureheretofore 'men-.- tioned." Pressure onfiuidlfl" tran'smittedfto.member" 3'6 exert'ssufficient force on pink to" prevent its withdrawalexcept when the glift ing; ring 30" raisesmember- 3B sufiicientl'yagainst the' force'on-pin Hr by-"borefi'l' to reducatheliolding; forceon pin 45 and permit'i'tswithclrawal:

Fig. 4 illustrates how-the ports" 31*are' obtained by removing part ofthe cylindrical portion 35*of the reciprocable member 36% This" viewalsoillustrates how the" bolts" 39" are installed? at a skewed axis. toprovide the maximum. cross sec tiona-larea for' housing: 3i" and"maximumfluid reserve chamber:

Refering nowto Fig. 5; it will be observed that the pin #5 has been"withdraw from bore' 41' of the recipro'cable cylindrical member "'36"since the shoulder 29 of the piston-26' has lifted the reciprocabl'ern'lindricalfmember 36. slightlyf-by'means' oh theeliftingzringzankdiagrammaticalixz imFigzlZbi;

Eigzfiiillustratessliomttie:reciprocahplstomzfi and.reciprocahlacylindrical'. member? 36.- move: downwardlsrlz'imtilseahring 63:. seals off pnrtsnsli so: as to"? entrap; thez fluid: 21:between; reciprocal pistomZB andireciprocahle cylindricai memberrafii.as was illustrated in Fig. 120. It will ob servecrithat. the: ring: 311-is: in the same position withrl-resnectto -shoulder 29' of the;-reciprocal piston: as:- it; was Fig.1. 5. This illustrates thatzthepiston; kfianmreciprocable member 316' NZEEIHDViIIgtiHLHHiSOILmillustrated, .the pin .45.: has been: released and is now being;

=. toward resetting; position: by means; of: its:

Eig; 7 illustrates? the; reciprocable cylindrical"?v memheni 6*imitszlowermostipositiozrof the stroke whicinwasr shown;diagrammaticallyrin Fig; 1 2i;-

Figmli showsttheismciprocablercylindrical memse hersreturningtoritsr-formen positionv of; L as; show-n:(iiagrammal';icall-y- Fig;12e'.' Asshowm. tlievpin: 45 iszzliearing againstv the side" ofa'member3B and is ready to engage thezhore 41. of member:-

W when: its lifter ringz30: has been moved: fir-its extreme upperposition by: theshoulder 2&- of; piston:-2ir, showmin :F'igsi Q and:12f, aligning the: bore-M ofiamenrberjili: with: the-pin 45 sov that itscanibe easily-engaged therebysdue to the' resilient.

biasingtmeans-im Member: 361s then: renderedinoperative' and piston 26'continues: its-constant; reciprocation untilrthe -operator again":pulls: pin- 45;.. It shouldbe= noted that: the. operator: ap-- plies;a;constant v tensiontto: pin- 45 but that. it;

cannot; beactuated until. liiterrring- 30* is= engaged:

byvshoulderifi of pistonzfi WhiChfITEdUCBSl-thfl; fierce; on: pin- 45-allowing it, to be. easily with-- drawn.,. This-action automaticallytimes thesap paratusand assures that the: chamber formed. be

tweens piston 2% and. cylinder 36: is full of 'fiu-id andawi-lliprovidc: themaximumstroke:

.9 I illustrate. a modification: of my. dea vicewhich; provides a.doublestrokeaction; or

4 asmnltiplicationrot the length: of powerrstrokew tonany mach i-neause,depending upon the-arsrangement chosen.-. this modification, ansothercpiston r5fi' -isprovided which isslidableand' recinrocable. withinthev reciprocable. cylindrical? memberifi and sealed.- therebetweenby'means ofE-J seal fifit. Resilient-means 5 is biasingpiston 5i to-its:uppermostiposition so that'z the lower:sunfaceroflthe.relatively:reciprocablespistom 56- and. member36-are.f1ush.-. It should-hemmed that; the fiuidll is, not; illustratedwithinthe cpl-ins der. 35, so. that;. ther construction. may he more;easilyiobserved; I Fig; -Lo=illustrates thisarrangement at -the;:bote.-tom. of. the stroke: with a stop 61 fastened; to *the *1 ringy38: by:means of. bolts; 8:8 's.o=.tas":to limit the;

movement. of: reciprocable member "36 ,1 which imturn .lcauseszthe'reciprocabl'e piston. Mites-move: downwardly compressing. resilientmeans 51, be cause oi the reciprocating action oi piston 26.

It' -wfll i be obvious to those skilled in the art; that the-reductioninareaof reciprocablepiston 56 over the-reciprocatingpiston-26 willcauses." greater movement. of'reciprocjable piston 56 than. isaccomplished in the devices of" my" previous illustrations. This can beutilized" to provide; a. greater; stroke for anyv machine use by. meansof stop 61..or variablepressure or stroke depending. upon whetherthereciprocable. members. 3'6? or piston. are. stopped, sothatjreciprocablea piston 56 or cylindrical member 3'6 can be caused tooperate in the sequence dependentupon the pressure on their relativeparts. Conversely, if a plate is placed across the faces of threlatively reciprocable member 36 and piston 56 an apparatus will beprovided which is identical in stroke characteristics to the device ofFig. 1 through Fig. 8.

Fig. 11 illustrates a modification of my devices Figs. 1 through 8,which permits the release of the reciprocable cylindrical member 35 inthe event it gets jammed after the port area is sealed oil. It will beobvious to those skilled in the art, that threading the plug [46 out ofthe bore [4| permits the ball M2 to uncover the bore I46, so that theentrapped fluid can be relieved to permit a resumption of the machineoperation. While Ihave shown this unit directly under the cylinder ofthe machine, it will'be obvious to those skilled in the art that it canbe positioned with a connecting passage to connect with the fluid 21. Itwill be 'also obvious that any type of relief valve would suiiiceproviding its sealed area was small so that the force on the valve wouldbe low despite the'high fluid pressure.

On Fig. 13I have illustrated my apparatus 28 as it would appear whenoperably mounted to an end-wheel gap-type press 21 of the same generalcharacter'as is illustrated in Fig. 13 of my Patent No. 2,364,011.Actuating apparatus replaced the conventional clutch l3l andeliminatedthe non-repeat and clutch actuating linkage I32, illustrated in thatpatent, as actuating button 45 of my present device is readily operatedsince it is in juxtaposition to the working area 22} A furthercomparison of the installation of clutch assembly I3l to press" l2! ofmy former patent will reveal that whereas actuating apparatus' is acomplete sub-assembly mounted to the press 2! and eccentric 24 of shaft44 after flywheel 23 and shaft 44 have been previously assembled to thepress 2!, clutch [3i must bev assembled to the press 12! prior toflywheel 130 and linkage I32 must then be adjusted on the press I31. Itwill also be obvious, to one skilled in the 'art, that in my presentinvention, shaft 44 is continuously revolving and pitman arm iscontinuously reciprocating with upper piston 26, so that only theinertia of the reciprocable ported cylinder 36 must be overcome when themechanism is actuated, whereas in my former patent, the inertia of thelong crankshaft; pitman arm and clutch mechanism must also be overcomeby clutch [3]. While I am here illustrating my device as applied topunch presses because of its unusual advantages relative thereto, itwill be obvious to one skilled in the art, that it can be employed inall like machine applications.

In accordance with this application of my invention, I employ theeccentric crankpin 24 at the end of the crankshaft 44 which drives thepitman arm 25 connecting the crankshaft 44 to my apparatus for causing areciprocable movement. As illustrated, reciprocable cylinder 33 becomesthe ram 36 when my device is applied to press-working machine tools, butit can be any reciprocable element on any machine.

As described previously, actuating apparatus 20 isa completelyself-contained unit within the separable housing 3! which with pitmanarm 25 can be removed from and assembled to the press frame 2| as anoperable unit assembly. This is accomplished by sliding pitman arm 25 onto the eccentric 24 of shaft 44 and attaching the four hold-down bolts39. Actuating apparatus 20 is 20 has then operable by actuating button45 without other attachments or operations.

It will now be obvious, to those skilled in the art, that assembly 20 ismore compact and easily installed when compared with other apparatus orclutches for providing a reciprocable action in press-working or othermachines. This arrangement provides a suitable sub-assembly for the massproduction techniques as well as a rapid means for servicing theapparatus by substituting bench tear-down and inspection for the morecostly servicing and inspection while on a machine.

Referring again to Figures 9 and 10, it will be obvious to those skilledin the art, that the reduction in area of reciprocable piston 56 overthe reciprocating piston 26 will cause a greater movement ofreciprocable piston 56 than is accomplished in the devices of myprevious illustrations. This can be utilized to provide a greaterstroke, or in the event a drawing process on a pressworking machine isrequired, a single or double draw can be provided as stop 6'! can beremoved to permit the piston 56 or ram 36 to operate in the sequencedependent upon the pressure on their relative parts. For instance, thiswould mean in press operation, that if a solid die were used it would bebacked up by the bed of the press to provide a solid stop base. If itwere then to be engaged by ram 36, during its stroke, the inner ram 56would be caused to move downwardly, drawing metal or other materialtherebetween, while maintaining the metal under ram 36 under highpressure, so as to efiect a good single drawing operation. By suitabledie and resilient pressure pad design a double draw can be provided asthe resilientresisting force of the pressure pad under either ram 36 or56 could be varied to cause the other to operate first.

It will be obvious to those skilled in the art, that my device has manyapplications in machine design and I intend that all such applicationsbe included by the claims appended hereto.

I claim:

1. A clutch comprising co-operative driving and driven elements whichdefine a space for a fluid by which movement of one element may betransmitted to the other, and a chamber for a body of said fluid, one ofsaid elements being movable to establish and cut off communicationbetween said space and said chamber so that said elements may moverelatively to one another or be caused to move in unison by fluidtrapped between them.

2. A clutch comprising co-operating driving and driven elements whichdefine a space for a fluid by which the movement of one element may betransmitted to the other, a chamber for. a body ofsaid fluid, one ofsaid elements being movable to establish and cut 01). communicationbetween said space and said chamber, whereby to control the transfer offluid between said space and saidchamber so that said elements may moverelatively to one another or be caused to move in unison by fluidtrapped between them, and meansfor maintaining the fluid in said chamberunder pressure.

3. A clutch comprising co-operating driving and driven elements whichdefine a space for a fluid by which movement of one element may betransmitted to the other, and a chamber for a body of said fluid, one ofsaid elements being ported and being movable to establish and cut offcommunication between said space and said chamber, whereby to controlthe transfer of'fiuid between said space and said chamber so that saidelements may move relatively to one another or be caused to move inunison by fluid trapped between them.

4. A clutchcomprising co-operating reciprocable driving and drivenelements which define a space for a fluid by which the movement of oneelement may be transmitted to the other, and

a space for a fluid by which the movement of one element may betransmitted to the other, said elements being coaxial and one beinglocated within the other, and a chamber for a body of said fluid, one ofsaid elements being ported and being movable to establish and cut oflcommuni v cation between said space and said chamber, whereby to controlthe transfer of fluid between said space and said chamber so that saidelements may move relatively to one another or be caused to move inunison by fluid trapped between them.

.6. A clutch comprising co-operating driving and driven elements whichdefine a space for a fluid by which the movement of one element may betransmitted to the other, a chamber fora body of said fluid, one of saidelements being ported and being movable to establish and cut offcommunication between said space and said chamber, whereby to controlthe transfer of fluid between said space and said chamber so that saidelements may move relatively to one another or be caused to move inunison by fluid trapped between them, and means for placing the fluid insaid chamber under pressure.

7. A clutch comprising co-operating driving and driven elements whichdefine a space for a fluid by which the movement of one element may betransmitted to the other, a chamber for a body' of said fluid, one ofsaid elements being ported and being movable to establish and cut offcommunication betweensaid space and said chamber, whereby to control thetransfer of fluid between said space and said chamber so that saidelements may move relatively to one another or be caused to move inunison by the fluid trapped between them, and an air inlet valve forconnecting said chamber to the atmosphere so that air may be drawn intosaid chamber to place the fluid therein under pressure.

' 8. A clutch comprising a driving element and a driven element, one ofsaid elements being in: the form of a reciprocal piston and the otherof,

said elements being in the form of a reciprocable cylinder, a fluidchamber, an air inlet valve connecting said chamber to atmosphere, andmeans for establishing and cutting oiT communication between saidcylinder and chamber, whereby to control the transfer of fluid betweensaid cylinder and chamber in such a manner that said piston and cylindermay move relatively to one another or be caused to move in unison byfluid trapped between them.

9. A clutch comprising a driving element and a driven element, one ofsaid elements being in the form of a reciprocal piston and the other ofsaid elements being in the form of a reciprocable cylinder, a fluidchamber, means for maintaining the fluid in said chamber under pressure,

and means for establishing and cutting ofi communication between saidcylinder and chamber,

whereby to control the transfer of fluid between said cylinder andchamber in such a manner that said piston and cylinder may moverelatively to one another or be caused to move in unison by fluidtrapped between them. i

10. A clutch comprising a driving element and a driven element, one ofsaid elements being in the form of a reciprocal piston and the other ofsaid elements being in the form of a reciprocable cylinder in which saidpiston is movable,

said cylinder having a ported section, a fluid chamber, and meansoperable at will, including the ported section of said cylinder forestablishing and cutting off communication between said cylinder andchamber, whereby to control the transfer of fluid between said cylinderand chamber in such a manner that said piston and cylinder may moverelatively to one another or be caused to move in unison by fluidtrapped between them.

11. A clutch comprising a driving element and a driven element, one ofsaid elements being in the form of a reciprocal piston and the other ofsaid elements being in the form of a reciprocable cylinder, a fluidchamber, and means for est-ab lishing and cutting 'ofi communicationbetween said cylinder and said chamber, whereby to control the transferof fluid between said cylinder and chamber in such a manner that saidpiston and cylinder may move relatively to one another or be caused tomove in unison by fluid trapped between'them.

12. A clutch comprising a driving element and a drivenielement, one ofsaid elements being in the form of a, reciprocal piston and the other ofsaid elements being in the form of a reciprocable cylinder, a fluidchamber, and means including said cylinder for establishing and cuttingoff communication between said cylinder and said chamber, whereby tocontrol the transfer of fluid between said cylinder and chamber in sucha manner that said piston and cylinder may move relatively to oneanother or be caused to move in unison by fluid trapped between them.

13. A'clutch comprising a driving element and a driven element, one ofsaid elements being in the form of a reciprocal piston and the other ofsaid elements being in the form of a reciprocable cylinder, saidcylinder having a ported section, a fluid chamber, and means includingthe ported section of said cylinder for establishing and cutting oifcommunication between said cylinder and chamber, whereby to control thetransfer of fluid between said cylinder and chamber in such a mannerthat said piston and cylinder may move relatively to one another or becaused to move in unison by fluid trapped between them.

14. A clutch comprising a, driving element in the form of a reciprocalpiston and a driven element in the form of a reciprocable cylinder, saidpiston being operable within said cylinder and cooperating therewith todefine a space for fluid by which the movement of said piston may betransmitted to said cylinder, a chamber for a body of said fluid, andmeans for establishing and cutting off communication between said spaceand said chamber so that pistonand cylinder may move relatively to oneanotheror be caused to move in unison by fluid trapped be-.

tween them.

the form of a reciprocal piston and a driven eleinent in the form of areciprocable cylinder, said"- piston being operable within said cylinderand co-operating therewith to define a space forfluid by which themovement of said piston may be transmitted to said cylinder', and achamber for: a body of said fluid, said cylinder being movable toestablish and cut ofi communication between said space and said chamberso that said piston and. cylinder may move relatively to one another or.be caused to moveinu'nison. by fluid trapped between them;-

Lfi. A clutch-1 comprising adrivin'e element'i'n' the; form-of: areciprocal piston anda driven. el'ement in the form of a reciprocablecylinderrhav ing a ported section, said piston being operable withinsaid cylinder and co operating' therewith to define; a. space for fluid:by which the move-' ment. of said piston may be transmitted to saidcylinder, and achamber for a body of said fluid, said cylinder beingmovable sothat said ported section may: establish..-a'ndi cutJoii:communication. between said spaceandisaidzchamber so that said pistonand cylinder may move relatively to one another or; be' caused tomove inunison by fluid trappedabetween: them;

1'21, A*-.clut'ch. comprising a; driving element in theformof' a:reciprocal piston and asdriven ele ment. inn-the: fornn of a1reciprocabl'e cylinder having: a'. portedz section; said. piston beingoperable; within; said: cylinder: and. co operating therewith to definea; space: for: fluidi by' which the: movementl of; said piston; may be:transmitted to: saidcylinder; at chamber for a body of said 2 fluid;said" cylinder: being movable so that said ported section may establishand cut off communication-be-- tween. said; space and.:said.chamber sothat said piston; and; cylinder may move relatively: to oneanother'or'becaused to move inrnnisonby flnid. trappedzllietween; them, andmeans:formaintaineing. t-lcreufl'uid: in said: chamber. under pressure.

18.. m clutch; comprising as driving: elementi the: form of anreciprocalpiston/and. a driven: ele:-- ment. in the" fornrof? a reciprocabl'e'cylinder: hav ingraaportedz section, said piston beingi'operablewithinsaid cylinder and .cooperati-ng: therewith to: define a: space:for-fluid by which: the move ment of said-.pistonmay-be transmitted.-.to: said cylinder; a2. chamberrfor' ELhOdY: of: said fluid, saidcylinder? being movable so that saidlported sec-- tionzmay establish.andicut.ofizcommunicatiombetween said: space: and: said. chamber so.-that: said piston; and cylinder may move relatively, to; one" anotheror: be: caused to: move: in: unisonby: fluid trappedsbetweemthem;andianz air inlet; valve: in:saidzcliamberthrongrrwhichthetlatter:communir cates:withithezatmosphere.

19;: A; clutch comprising; co'roperating; driving, and; driven elementsone. of said elements;being inlthe form of acreciprocal; piston, andtbe:other of said elementsrbeing-inthe" former a,reciprocablecylindensaidlpiston and' cylinderdefining aspace for-:a'fluid by which the movement oi: one may betransmitted: to: the other; achamber; for a body ofgsaidj-fiuid; said cylinderrbeingmovable: to;establish: and cut offifcommunicationtbetween saidspacez andrsaid:chamber: so --that"said:piston and: cylinder 'maymovecrelatively to: oneanother? or" be caused tOfmOVGTiII unison by fluid trapped betweenthem;andi-means for holdingrsaid; cylineder: against movement in the:position; which it establishescommunication between: said space andsaidchamber'.

20. A clutch comprising co-operating drivine andidriven elements; one ofsaid-elements: being inthe' form of a reciprocai piston and the other 7512 of said elements being: in theiorm of a reciprocable cylinder havinga ported section, said piston being movable within said cylinder andco-operating therewith to define a space for a fluid by which themovement of one may be transmitted to the other, achamber for a body ofsaid fluid, said cylinder b'eing movable so that said ported sectionmayestablish and out off communication between said space and said chamberso that said" piston and cylinder may move relatively to one another orbe caused to move in unison by flu-id trapped between them; and meansfor holding said cylinder against movement in the position inwlfiichsaid ported section establishes communication between said spaceand said chamber.

21. A clutchcomprising co-operating driving and driven elements, oneof'saidelements being in theformof" areciprocal piston and the other ofsaidelements being in the form of a reciprocable cylinder having aported section, said piston being movable within said cylinder and co--operating therewith t'o-define a space for a fluid" by whichthe'movement of-onemay-be transmitted to the other, a chamber for a bodyof'said fluid, said cylinder being movable so that said ported" sectionmay establish and cut on commu' nicat-ion between said space and saidchamber" so that saidpistonand cylinder may moverela tively to oneanother or be caused to move in unison byfiuidtrapped'between them,means for holding said cylinder against movement in the position inwhich said ported section establishescommunication between said spaceand said chamber, andmeans'for maintaining; the fiuid in saidcliamberunder' pressure.

22. A clutch comprising cooperating driving and driven elements, thedriving eiemen't' being.

in the form of a reciprocal piston and the driven element beingin-theform of a re-ciprocablesleeve surrounding said piston-andhaving aported'sec tion; a second" driven element comprising a' free pistonslidable within'thesleeve; saiddriving and driven elements defining: a'space for fluid by which the movement of the driving element'may be'transmitted'to the'driven elements; a chamber forabodypfsaidfluid, saidsleeve being movable soth'at theporte'ds'ection'may establish andcut'on? communication between said" space and said chamlrfer so thatsaidelements may move relas tively'to' one another or be caused to movein unison, saidfree pistonhaving asmaller'efiective area thalftlle firstpistonwhereby when communication-is cut offby said sleeve motion will betransmitted'by' the first piston through the fluid tosaid free'pistonin=proportionto their respec-- tive areas.

23. A device of the character d'escribed"-com prismg'a:housin shayi-ng.a chamber" therein for the cylinder ports move and" by whichthey areclosed when said icylinderi moves to another posi piston and' theiclosed end 'wa-llof said cylinder so that: said cylinder maybedriven-through said trapped liquid on movement oi 'said piston one"direction, and means-for releasably se'curin'gsaid' :cylindr to saidhousing to hold said cylindertion, wherebyliquid may be trapped; in thelast-- named position of said cylinder, between saidthe cylinder portsmove and by which they are closed when said cylinder moves to anotherposition whereby liquid may be trapped, in the lastnamed position ofsaid cylinder, between'said piston and the closed end wall of saidcylinder so that said cylinder may be driven through said trapped liquidon movement of said piston in one direction, a member adjustablyconnected to said cylinder in position to be engaged by said piston whensaid piston is moved in the opposite direction to move said cylinder inthe opposite direction, and means for releasably securing said cylinderto said housing to hold said cylinder against movement relative to saidhousing when said cylinder is in said one position.

25. A device of the character described comprising a housing having achamber therein for containing a liquid, a cylinder reciprocable in saidhousing, a piston reciprocable in said cylinder, means for reciprocatingsaid piston, said cylinder being closed at one end and having portsadjacent said one end through which liquid may fiow back and forthbetween said chamber and said cylinder when said cylinder is in oneposition, said housing having a portion into which the cylinder portsmove and by which they are closed when said cylinder moves to anotherposition, whereby liquid may be trapped, in the lastnamed position ofsaid cylinder, between said piston and the closed end wall of saidcylinder so that said cylinder may be driven through said trapped liquidon movement of said piston in one direction, a check valve in saidhousing through which air may be admitted to said chamber, a detent forreleasably securing said cylinder to said housing to hold said cylinderagainst movement relative to said housing when said cylinder is in saidone position, and resilient means biasing said detent toward operativeposition.

26. A device of the character described comprising a housing, a cylinderreciprocable axially in said housing, a first piston reciprocable insaid cylinder, said cylinder being closed at one end, a second pistonreciprocably mounted in the closed end of said cylinder, said first andsecond pistons defining a space for a liquid, a chamber for a body ofsaid liquid, means adapted to connect said chamber with said space toperunit fiow of; liquid back and forth between said chamber and space,means operable on movement of said cylinder in one direction to cut offcommunication between said chamber and space whereby to trap liquidbetween the two pistons to permit the first piston on movement in onedirection to impart movement to the second, means for reciprocating saidfirst piston, and means for biasing said second piston toward said firstpiston, the areas of the opposed faces of the two pistons beingdifferent, and the second piston having the smaller area.

2'7. A device of the character described comprising a housing, acylinder reciprocable axially in said housing, a first piston'reciprocable 14 in said cylinder; said cylinder beingzclosed-at oneend, a second piston reciprocably mounted in the closed end of saidcylinder, said first and second pistons defining a space for a liquid, achamber for a body of said liquid, means adapted to connect said chamberwith said'space to permit flow of liquid back and forth between saidchamber and space, means operable on movement of said cylinder in onedirection to cut off communication between said chamber and spacewhereby to trap liquid between the two pistons to permit the firstpiston on movement in one direction to impart movement to the second,means for reciprocating said first piston, and means for biasing saidsecond piston toward said first piston, the areas of the opposed facesof the two pistons being different, and the second piston having thesmaller area, means for releasably securing said cylinder to saidhousing to hold said cylinder against movement relative to said housing,and a stop secured to said housing for limiting the movement of saidcylinder when it has been released and the first piston is driving thesecond piston.

28. A device of the character described comprising a housing having achamber therein for containing a liquid, a cylinder reciprocable in saidhousing, a first piston reciprocable in said cylinder, means forreciprocating said first piston, said cylinder being closed at one endand having ports through which liquid may flow back and forth betweensaid chamber and said cylinder when said cylinder is in one position, asecond piston reciprocably mounted in the closed end of said cylinder,and means for biasing said second piston toward said first piston, saidhousing having a portion into which the cylinder ports move and by whichthey are closed when said cylinder moves to another position, wherebyliquid may be trapped in said cylinder between the two pistons so thatsaid second piston may be driven through the trapped liquid on movementof said first piston in one direction, the areas of the opposed faces ofthe two pistons being different, and the second piston having thesmaller area.

29. A device of the character described comprising a housing having achamber therein for containing a liquid, a cylinder reciprocable in saidhousing, a first piston reciprocable in said cylinder, means forreciprocating said first piston, said cylinder being closed at one endand having ports through which liquid may flow back and forth betweensaid chamber and said cylinder when said cylinder is in one position. asecond piston reciprocably mounted in the closed end of said cylinder,and means for biasing said second piston toward said first piston, saidhousing having a portion into which the cylinder ports move and by whichthey are closed when said cylinder moves to another position, wherebyliquid may be trapped in said cylinder between the two pistons so thatsaid second piston may be driven through the trapped liquid on movementof said first piston in one direction, the areas of the opposed faces ofthe two pistons being different, and the second piston having thesmaller area, and means for releasably securing said cylinder to saidhousing to hold said cylinder against movement relative to said housingwhen said cylinder is in said one position.

30. A device of the character described comprising a housing having achamber therein for containing a liquid, a cylinder reciprocable in I5housing, a; first piston reciproclble in said cylinder,- means forreciprocating: said first piston, said cylinder being closed: at one endand having ports through which l-icmid may flow back and forth betweensaid-chamber and 'SQsi'Q'QYIi-H der when said cylinder is in oneposition, a secendpiston: reciprocahl-y mounted in the closed end oisaid cylinder, and for biasing said second piston toward said firstpiston, said housmy having a; portion into which the cylinder ports moveand by whichthey are: closed when said cylinder moves to anotherposition, whereby liquid may be trapped in: saidcylinder between the twopistons so that said second piston may driven through the trappedliquid; on movement of said first piston in one direction, the areas ofthe opposed faces of thevtwo pistons being difierent and thesecondpiston. how his the smaller vaxes, and means for neleassbly securingsaid cylinder to said housing to hold; 20

said cylinder against movement relativeto said REFERENCES CITED Thefollowing references are of record in the 16 file of this patent:

UNITED STATES PATENTS Number Name Date 414,910 Krause Nov. 12, 1889662,515 Yale Nov. 27, 1900 2,135,011 McGauchie Nov. 1, 1938 2,227,279Smith Dec. 31, 1940 2,296,283 Jorgensen Sept. 22, 1942 234 11118D'eloghia June 22, 1948 2,446,862 Wilders Aug. 10, 1948 249,886 WorthAug. 24, 1948

